Push rod with ball check valve



Aug. 11, 1964 L.. J. VAN sLooTl-:N 3,144,010

PUSH ROD WITH BALL CHECK VALVE v Filed Aug. 17, 1962 Biff@ ATTORNEY United States Patent O 3,144,010 PUSH ROD WITH BALL CHECK VALVE Louis J. Van Slooten, West Olive, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Aug. 17, 1962, Ser. No. 217,596 Claims. (Cl. 12S- 90) This invention relates to lubricating systems for internal combustion engines, pumps, etc. employing hydraulic Valve lifters and push rods for operating valves and the like mounted in the cylinder head through one or more intermediate linkage elements such as valve rockers, and wherein the bearing surfaces of the valves, rockers, etc. are to be supplied with oil via the push rods from the hydraulic valve lifters which receive their supply from the main engine oil pressure system. An arrangement of this type which has proven highly successful is disclosed in U.S. Patent 2,818,050 to Papenguth.

In those installations wherein the hydraulic valve lifter and push rod operate generally horizontally, however, a problem has existed in preventing the oil in the reservoir chamber of the hydraulic valve lifter from draining out during an engine shutdown, with consequent noisy engine starts due to air getting into the pressure chamber in the bottom of the lifter. Various efforts and proposals to eliminate this difficulty have heretofore been made including reducing the oil inlet holes in the lifter plunger to a single such hole, the provision of a check valve inwardly of the plunger from the inlet holes, baffling of the plunger reservoir chamber, etc.

While many of these schemes have been functionally effective, I have found thatthe same result can be accomplished by a simple addition to the push rod so as to prevent its serving to vent the plunger reservoir chamber in the lifter during an engine shutdown. An additional advantage of my invention lies in the fact that the desired result is accomplished whether a perforate or imperforate metering valve is used in the lifter reservoir chamber to control oil ow therefrom to the rocker bearing surfaces via the hollow push rod. Briefly stated, the invention comprises the addition of a check valve and seat therefor within the lower end of the push rod. Means may simply be provided, as by indenting the side wall of the push rod above this check valve, to limit travel of the latter in operation.

The invention will be more clearly understood from the following description, having reference to the attached drawing illustrating two slightly different forms thereof, wherein:

FIGURE 1 is a cross-sectional view of a portion of an internal combustion engine incorporating a cam driven hydraulic valve lifter and associated hollow push rod through which oil for lubrication purposes is delivered, but drain-out of the lifter reservoir chamber is prevented in accordance with my invention;

FIGURE 2 is an enlarged view of the push rod assembly per se shown in FIGURE l;

FIGURE 3 is a cross-sectional View taken substantially along the line 3-3 of FIGURE 2;

FIGURE 4 is a view similar to FIGURE 2 but showing a modification of the invention; and

FIGURE 5 is a cross-sectional view taken substantially along the line 5-5 of FIGURE 4.

Referring now in detail to FIGURES 1, 2 and 3, there is shown a portion of an engine crankcase 1 in which is journaled a rotary cam 2 for reciprocating a hydraulic valve lifter 3 and its push rod 4 to actuate an engine poppet valve or other part (not shown) via a rocker or other linkage (not shown) to the right of FIGURE 1. It will be noted that the lifter 3 and push rod 4 have their axes 3,144,010 Patented Aug. 11, 1964 ice substantially horizontal (being shown inclined only slightly therefrom), a requirement common to operation of of this invention only in that the reservoir chamber 5 within the lifter plunger 6 has but a single inlet 7 for eX- ternally supplied hydraulic uid. This fluid, in the form of oil from the engine main oil pressure lubricating system, is supplied to the lifter via a gallery 8 in the crankcase 1. A port 9 connects this gallery to a recess 10 in the bore 11 of the crankcase in which the lifter is slidably reciprocable. An external annular groove 12 about the periphery of the cylindrical body 13 of the lifter is in registry at all times with the recess 10 and is connected with the bore of the lifter body via one or more ports 14 20 on the plunger, which shoulder forms a seat for a' through the side thereof. An annular groove 15 surrounding the plunger 6 is in registry at all times with the ports 14 and is connected with the reservoir 5 via the aforementioned single inlet port 7.

Closing the outer end of the plunger 6 is apush rod seat 16 which is centrally apertured at 17. This aperture 17 defines the sole outlet for passage of oil to the exterior of the lifter 3 from its reservoir chamber 5. Seated in j thrust transmitting engagement with the push rod seat 16 is the end 18 of the push rod 4, which push rod is hollow and has an opening 19 at this end in communication with the outlet 17 of the lifter. Inwardly of the plunger from the push rod seat 16 is an internal shoulder metering valve 21. This valve 21 is movable away from shoulder 20 and into abutment with the push rod seat 16 in response to engine oil pressure inwardly of the reservoir chamber 5 from the metering valve 21. The valve 21 is shown in the form of a flat disc or plate, and its abutable surface 22 on the push rod seat 16 may be cylindrically curved as disclosed in the aforementioned Papenguth patent so that when the metering valve is in abutment therewith oil flow through the push rod seat aperture 17 and into the push rod is at a restricted or metered rate. The metering valve 21 differs slightly from that in the Papenguth patent in having a small aperture 23 therethrough, eccentrically located so as to be radially outward thereof from the metering valve abutting surface 22 on the push rod seat. The purpose of this orifice 23 is to permit pneumatically checking proper assembly of the lifter 3 in production, and does not have any operative function in the lifter during engine operation. Its presence, however, without the check valve action within the push rod hereinafter described tends to serve as a vent for the reservoir chamber 5 during an engine shutdown, which would allow oil to drain out therefrom and cause noisy starts.

The push rod 4 comprises two longitudinally joined parts 24 and 25 concentrically disposed relative to each other at their adjacent ends, the end 18 of the outer part 24 being spaced a substantial distance from the end 26 of the inner part. Between the two ends 18 and 26, within the part 24, is located a ball check valve 27. As shown in its solid line position, this ball 27 is in engagement with a seat 28 provided therefor interiorly of the rod part 24 adjacent the opening 19. In such position the ball 27 serves both to block drainage of any contained oil within the push rod into the lifter reservoir chamber 5, and to prevent venting of such reservoir as might otherwise allow oil to drain out of the reservoir chamber via its inlet port 7. Under engine oil pressure conditions within the reservoir chamber during engine operation, however, the ball 27 is displaced from its solid line position shown to the indicated dotted line position in abutment with the end 26 of the inner push rod part 25. It will also be appreciated that the ball 27 is of substantially smaller diameter than the bore 29 of the push rod part 24, so that oil flow past the'ballis permitted during engine operation. Abutment with the end 26 is provided in order to limit the opening travel of the ball 27, such abutment occurring at one or more indentations 30 of the end 26 of the inner push rod part. These indentations are also seen in FIGURE 3. The opposite end 31 of the push rod has an outlet 32 for the oil to reach the rocker or other surfaces of the parts to be lubricated, and adjacent this end there is provided a vent hole 33 in the side of the rod.

A modified form of push rod is shown in FIGURES 4 and as comprising two longitudinally adjacent parts 24 and 25 welded or otherwise secured together at a cornmon parting line 34. These parts may be identically formed, after which the part 24 is indented at 30 to provide the stop for the ball 27. Also, this push rod may be made in one piece, eliminating the parting line 34 by first forming a cylindrical tube of proper length and upsetting the ends 18 and 31 after insertingthe ball 27. The inlet opening, outlet and Vent corresponding to those in the rst form described are shown at 19', 32' and 33', respectively.

While only two constructional forms of my invention have been shown for purposes of illustration, it is appreciated that numerous minor changes in the construction and arrangements of the parts may be made without departing from the spirit and scope of the invention as defined in the following claims.

I claim:

- 1. The combination with a hydraulic valve lifter having a chamber with a single inlet for reception of externally supplied hydraulic Huid and a push rod seat at one end of said chamber having an aperture deiining the sole outlet for passage of said fluid from the chamber to the eX- terior of the lifter, of a hollow push rod in longitudinal thrust transmitting engagement with said rod seat adjacent said outlet, said rod having an opening in its rod seat engaging end communicating with said outlet, a iluid outlet remote from said end, a valve seat interiorly of the rod adjacent said opening, and a check valve engageable with said valve seat to block communication between said chamber and the interior of the rod, said valve being movable away from said valve seat in response to iluid pressure in the chamber to accommodate iiow therefrom into the rod.

2. The invention of claim 1, together with a metering valve and an annular seating shoulder therefor in said chamber, said metering valve being movable away from said shoulder and into abutment with said rod seat to restrict How of hydraulic iiuid through said outlet from the chamber and having an aperture intercommunicating i said chamber and outlet when seated on said shoulder.

3. In combination with a hydraulic Valve lifter having a chamber for reception of externally supplied hydraulic Huid and a push rod seat closing one end of said chamber, said push rod seat having an outlet for passage of uid therethrough from the chamber, a hollow push rod in longitudinal thrust transmitting engagement with said rod seat adjacent said outlet, said rod having an opening in its rod seat engaging end communicating with said outlet, a Valve seat interiorly of the rod adjacent said opening, a fluid outlet remote from said rod end, and a valve movable into and out of engagement with said valve seat to accommodate fluid ilow through said opening only in the direction from said chamber.

4. The invention of claim 3, wherein said push rod has Y? a side wall with an indentation axially spaced from said end, said indentation being engageable by the check valve to limit its movement away from said seat.

' 5. The invention of claim 4, wherein said push rod comprises two longitudinally joined parts having their adjacent ends concentrically disposed relative to each other,

said indentation being located at the end of the inner of said parts within the other part. p

References Cited in the le of this patent UNITED STATES PATENTS 2,667,149 Purchas et al. Jan. 26, 1954 2,857,895 Scheibe Oct. 28, 1958 2,935,059 Thompson May 3, 1960 3,054,392 Thompson Sept. 18, 1962 

1. THE COMBINATION WITH A HYDRAULIC VALVE LIFTER HAVING A CHAMBER WITH A SINGLE INLET FOR RECEPTION OF EXTERNALLY SUPPLIED HYDRAULIC FLUID AND A PUSH ROD SEAT AT ONE END OF SAID CHAMBER HAVING AN APERTURE DEFINING THE SOLE OUTLET FOR PASSAGE OF SAID FLUID FROM THE CHAMBER TO THE EXTERIOR OF THE LIFTER, OF A HOLLOW PUSH ROD IN LONGITUDINAL THRUST TRANSMITTING ENGAGEMENT WITH SAID ROD SEAT ADJACENT SAID OUTLET, SAID ROD HAVING AN OPENING IN ITS ROD SEAT ENGAGING END COMMUNICATING WITH SAID OUTLET, A FLUID OUTLET REMOTE FROM SAID END, A VALVE SEAT INTERIORLY OF THE ROD ADJACENT SAID OPENING, AND A CHECK VALVE ENGAGEABLE WITH SAID VALVE SEAT TO BLOCK COMMUNICATION BETWEEN SAID CHAMBER AND THE INTERIOR OF THE ROD, SAID VALVE BEING MOVABLE AWAY FROM SAID VALVE SEAT IN RESPONSE TO FLUID PRESSURE IN THE CHAMBER TO ACCOMMODATE FLOW THEREFROM INTO THE ROD. 